This invention relates to an exercise machine. More specifically, this invention relates to an exercise machine of the type wherein a platform or carriage is movable mounted to a frame and spring biased in one direction along a path of motion.
Exercise machines are well known in which a platform is supported for reciprocating motion along horizontal tracks on a frame. The platform is connected by springs to one end of the frame. The springs provide a resistive force against motion of the platform in one direction along the tracks and a restorative force aiding motion of the platform in the other direction along the tracks. Typically, a user sits or lies on the platform and pushes with his or her legs against a footbar on the frame In addition, pulley-mounted cords or ropes are connected to the platform for enabling other types of exercises, for example, using the arms, in counteraction to the resistance provided by the springs.
Machines of this type are designed for exercising so called core muscle groups, namely those muscles of the torso which stabilize the person during normal daily activities such as standing, sitting, and walking. These machines enable the stretching of many muscle groups together, without exceeding a normal or natural range of muscle stretching.
Exercise machines of the above-described type are disclosed in U.S. Pat. No. 5,338,278 to Endelman, U.S. Pat. No. 5,066,005 to Luecke, U.S. Pat. No. 4,884,802 to Graham, U.S. Pat. No. 3,892,404 to Martucci, U.S. Pat. No. 3,770,267 to McCarthy, and U.S. Pat. No. 3,586,322 to Kverneland.
Known core-muscle-group exercise machines are generally ill-suited for exceptional individuals, particularly athletes The machines are built for individuals of average size and strength. When such machines are used by persons of extraordinary size and/or strength, the machines are either too small or insufficiently strong. For example, the platform sometimes derails if the forces exerted are too great.
Another disadvantage of conventional core-muscle-group exercise machines lies in the fact that adjustment of the cords or ropes, when accommodating individuals of different sizes, frequently results in unequal effective lengths of the cords or ropes. This inequality or asymmetry in machine action is disadvantageous insofar as muscle strains may result.
Adjusting the spring forces in conventional platform-type exercise machines is generally inconvenient, requiring that the user stop and change position, particularly where a machine is being used in a demonstration to several student users. Depending on the numbers of students and the classroom space, the students frequently cannot witness what adjustments are made. The springs and the adjustment thereof are obscured by the frame of the machine.
All limb movement necessitates trunk muscle recruitment via the reciprocal motion of the machine and user's body weight and spring resistance. Many exercise machines typically cause compressive loading on the spine in vertical positions. This type of loading causes degeneration of the spinal segments. With horizontal exercise machine of the movable platform type, spine, shoulder, hip, knee and ankle stability are ideal benefits which occur during developed or choreographed exercise sequences.
Often back patients exhibit trunk muscle atrophy and poor posture which can be changed by using low spring loading, with submaximal trunk loading as a result. The existing equipment however is not adaptable for the body length or body weight of many professional athletes who need an extreme amount of resistance to effect muscle hypertrophy.